Electrical Control of Uniformity in Quantum Dot Devices.

Area of Science:

• Quantum computing
• Semiconductor physics
• Quantum information science

Background:

• Scalable quantum processors require highly uniform quantum systems.
• Semiconductor quantum dot spin qubits are a promising platform for quantum computing.
• Quantum dots are sensitive to their local environment, posing uniformity challenges.

Purpose of the Study:

• To present a novel electrical method for achieving high uniformity in the intrinsic potential landscape of quantum dot devices.
• To demonstrate the stable tuning of quantum dot pinch-off voltages.
• To reduce variability in quantum dot arrays for improved scalability.

Main Methods:

• Utilized hysteretic shifts of gate voltage characteristics for electrical tuning.
• Demonstrated tuning of pinch-off voltages over hundreds of millivolts.
• Applied the method to homogenize pinch-off voltages in a linear array of four quantum dots.

Main Results:

• Achieved stable tuning of pinch-off voltages in quantum dot devices for hours.
• Reduced the spread in plunger gate pinch-off voltages by one order of magnitude.
• Significantly improved the uniformity of a linear array of four quantum dots.

Conclusions:

• The presented electrical tuning method offers a new tool for quantum dot device fabrication.
• This technique provides new perspectives for implementing scalable spin qubit arrays.
• Enhanced uniformity is critical for advancing semiconductor-based quantum computing.